2017-02-17 14:10+0100, Christian Borntraeger:
> while we still need to provide our private version of kick and wakeup
> to synchronize with some special cases, we can still enable the common
> code variant.
>
> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> ---
> arch/s390/kvm/kvm-s390.c | 12 ++++++++++--
> virt/kvm/kvm_main.c | 2 --
> 2 files changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 7cfd0dd..fa20686 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -2485,8 +2485,14 @@ static void kvm_gmap_notifier(struct gmap *gmap, unsigned long start,
>
> int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
> {
> - /* kvm common code refers to this, but never calls it */
> - BUG();
> + /*
> + * STOP indication is resetted when delivering interrupts. This
> + * is done before we handle requests, so we only "loose" this
> + * when we are still going to handle requests. In that case
> + * we no longer need that STOP indication.
> + */
> + __set_cpuflag(vcpu, CPUSTAT_STOP_INT);
> + kvm_s390_vsie_kick(vcpu);
I wouldn't put the kick into that function. On other architectures, the
function decides whether we should call an operation that actually
forces the exit. e.g. x86 and arm do
return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE
(which also contains an optimization, because they will not kick a VCPU
twice or do a kick for a VCPU outside the guest mode.)
There little point in having vcpu->mode if we do not use it here.
And we'd also like to use kvm_arch_vcpu_should_kick() for the same
decision in kvm_make_all_cpus_request(); basic idea:
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4f4d250e1f53..676c0636d73c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -163,10 +163,6 @@ void vcpu_put(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(vcpu_put);
-static void ack_flush(void *_completed)
-{
-}
-
bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
{
int i, cpu, me;
@@ -194,13 +190,13 @@ bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
smp_mb__after_atomic();
if (cpus != NULL && cpu != -1 && cpu != me &&
- kvm_vcpu_exiting_guest_mode(vcpu) != OUTSIDE_GUEST_MODE)
+ kvm_arch_vcpu_should_kick(vcpu))
cpumask_set_cpu(cpu, cpus);
}
if (unlikely(cpus == NULL))
- smp_call_function_many(cpu_online_mask, ack_flush, NULL, 1);
+ kvm_arch_cpu_kick_many(cpu_online_mask);
else if (!cpumask_empty(cpus))
- smp_call_function_many(cpus, ack_flush, NULL, 1);
+ kvm_arch_cpu_kick_many(cpus);
else
called = false;
put_cpu();
